Subject: Mobile Computing

Difficulty: Medium

Marks: 4 Marks

A virtual private network (VPN) is a network that uses a public telecommunication infrastructure, such as the Internet, to provide remote offices or individual users with secure access to their organization's network.

A VPN works by using the shared public infrastructure while maintaining privacy using security procedures and tunneling protocol.

The tunneling protocols VPN uses are:

• Layer Two Tunneling Protocol (L2TP).
• Internet Protocol Security (IPSec).

In effect, these protocols in sequence do:

• Encrypts data at the sending end.
• Send the data through a "tunnel".
• and decrypts it at the receiving end.

An additional level of security involves encrypting not only the data, but also the originating and receiving network addresses. Mobile VPN:

A mobile VPN is a network configuration in which mobile devices such as notebook computers or personal digital assistants (PDAs) access a virtual private network (VPN) or an intranet while moving from one physical location to another. An effective mobile VPN provides continuous service to users and can seamlessly switch across access technologies and multiple public and private networks. The functioning of an effective mobile VPN is transparent to the end user without compromising security or privacy. The foundation of a successful mobile deployment is a Mobile VPN (virtual private network) software that provides mobile workers with secure, reliable, remote access to network resources and information from virtually anywhere. Only a Mobile VPN is designed to deal with the unique challenges associated with mobile computing such as wireless security, performance and roaming.